Method of electrically detecting dangerous gases and apparatus therefor.



No. 892,241. PATENTED JUNE 30, 1908.

H. FREISB.

METHOD OF ELEGTRIGALLY DETECTING DANGEROUS GASES AND APPARATUS THEREFOR.

APPLICATION FILED JUNE 10, 1907.

2 SHEETS-SHEET 1- W/T/VESSES lNVENTOH x ,I W Mano b B) A TTOHNE) No.'892,241. PATENTBD JUNE 30, 1908. H. PRBISE.

METHOD OF ELEGTRIOALLY DETECTING DANGEROUS GASES AND APPARATUS THEREFOR.

APPLIOATION FILED JUNE 10,.1907.

2 SHEETS-SHEET 2.

wmvassss (NVENTOI? 9 g g I fiJeWLe/i m 4 y HEINRIEEH FREISE, OF BOGHUM, GERMANY.

EETHOD F ELEGTRICALLY DETECTING DANGEBOUS G-ABEB AND APPLRATUE W Specification of Letters latcna.

THEREFOR.

' Patented June so, loos.

Application sacrum 10, 1907. semi no. amaze.

To all whom it may concern: I it known'that I, HEINRICH Fanrsn, a

' citizen of the Empire of Germany, residing paratus Therefor, of which the following is a re s of light from said source of lig 'vide a primary circuit includin the sai and, if so preferred, other devices.

specification.

My invention consists of a method of electrically detecting an dangerous opaque or transparent gases an of actuating alarm devices and if so preferred also'other devices for removing the dan er or the like.

My invention furt er'consists of apparatus for carrying into effect the said met od.

According to my method a source of light, a-selenium cell and a device for rejecting t to said so enium cell are employed. I further (proselenium cell, so that normally t e resistance of the latter is reduced and a current of sufiicient strength circulates in the primary cirwit. The dangerous gas is passed across the rays of light and lf lt is opaque it will at once darken the selenium cell, so that the resistance of the latter will increase and the strength of the current circulating in the pricircuit will decrease. An electromag net 1s insertedin the primary circuit, so that it is normally energized for attracting its armature. I provide a secondary circuit, which is ada ted to be closed by the armature of said elhctromagnet on the same being released and it includes an electric alarm If actually dangerous opaque gas (such as for example smoke) is from some reason formed an passes across the rays of light, it will darken the selenium cell, when the strength of the current circulating in the primary circi'rit will be diminished, so that the electromagnet will release its armature, which is detached by a spring and closes the seconda circuit, whereupon the electric alarm will sound and the other devices, if there are any, will be-actuated. If the dangerous gas is transparent, such as foul gases in a colliery or the l1ke, I may provide means for passing a transparent band impregnated with suitable chemicals through the current of gas between the device for rojecting rays of light and the selenium cel j The said chemicals are of such a kind as to render under the action of the dangerous transparent gas the band more or less 0 aque, so that the same effect as described a ove is obtained. Or I may rovide means for chemically rendering the angerous transparent as more or less opaque, when the same ect will be attained. The chemical process for changing the dangerous transparent gas, may be for example a combustion.

I Wlll now proceed to describe my invention with reference to the accompanying drawing, in which- Figure 1 is a diagram of an apparatus for electrically detecting a dangerous opaque gas, such as for example smoke, Fig. 2 is a diagram of an apparatus for electrically detecting a'dangerous transparent gas, the secondary circuit being omitted, and Fig. 3 is a part of another apparatus for electrically detecting a dangerous transparent gas.

Similar letters of reference refer to similar parts throughout the several views.

In Fig. I I have shown an ap ratus for electrical detecting smoke or t e like in a room or uilding. u denotes a source of energy for supplying an electric incandescent 'lamp 1) with current.

rimary circuit o o is provided, which inclu es a source of current 1; (for example a battery), a selenium cell Z1 and an e-lectromagnet c of an known construction. The selenlum cell 6 is shown as disposed within a box 61* and exposed-to the rays of li ht emanating from the incandescent lamp through a convenient tube 6. A reflector b" may be disposed on the source of energy a for deflectin the rays of, light meeting it and for throwing them to the selenium cell 1). The tube 6 may be connected with two opposite tubes a and a, which are so bent as to ermit no foreign li ht to enter the tube b. The two opposite tubes a and a are referably so disposed, that any smoke pr need on the place from some reason can easily pass through them upwards while crossing or intercepting the rays of light that pass from the lam b to the selenium cell b. A secondary circuit m 0; a is provided, which (for example a attery), the armature d of the electromagnet c, an adjustable stop f and an electric alarm I of any known construction. The armature d is normally attracted by the 'electromagnet c and is arranged to be detached and pressed on the adjustable stop f by a spring e on the electromagnet c becoming too week. A hook 9 may be pro- 1s shown as com rising a source of current evided, which normally rests on the end of the armature (Z and is adapted to snap behind the latter when detached and to press it on the stop f, so as to cause the alarm I to continuously sound. For stopping the alarm I at any moment it is only necessary to turn the hook g upwards and to place it against a stop It. Where so preferred, a further device of any known construction may be placed under the control ofthe secondary circuit. For example a water pipe system ma be disposed in the res ectlve room or bui ding for extinguishing a ire in any known manner and of this ipe system only a tube 25 with a water cock and a supply tube t is shown in Fig. 1. A spring 1 may be provided for pressing the handle i on the plug of the Water cock k against a suitable stop 8 and thus maintaining the cock in its open state. vA con. venient bent lever p may be provided for en gaging with its upper arm a tooth r on a cam disk fastened on the plug of the cock is. The handle i can then be turned through an angle of 90 while straining the spring Z until the lever 12 snaps behind the tooth r and holds the plug in its closing position. Another bent lever n 0 may be provided and a spring g may press its horizontal arm n on a convenient insulated stop dis osed on the s ringressed armature m o the electric a arm while the upper vertical arm 0 merely leans against the lower arm of the bent lever p.

This apparatus operates as follows: All the parts occupy their normal ositions shown in Fig. 1, so that the ra s of ight projected from the incandescent amp I) to the selenium cell 1) reduce the resistance of the latter and the current circulating in the primary circuit v v is sufiiciently strong to energize the electromagnet c for attracting its armature d. The secondary circuit a: m in? is on the contrary broken, so that the electric alarm I is at rest and the water is shut off from the ipe system by the water cock 7:. Things will continue, as ong as everything is all right. Shouldsmoke be originated from some reason in the respective room or building and pass upwards throu h the tube a, across the tube 7) and through t e tube a ,it will intercept or weaken the rays of light passing through the tube b. In consequence of this the resistance of the selenium cell b will increase, and the strength of the current cirthe water cock 1c. Then the water thus ad water cock k may be closed by hand and be locked by the bent-lever p, while the horizontal arm n of the lever n 0 is made to engage the lug on the armature m. The hook g is turned downwards, so that its hooked end rests on the upper endof the armature d as is shown. I

In case no smoke but a dangerous transparent gas, such as foul gases in a colliery, is to be detected, a band w impregnated with a suitable chemical may be assed across the tube 1) on the place where t e curved tubes 0, and a cross the tube 1), aslis for exam le shown at Fig. 2. In this fi ure theban w is shown as passing upwar s from a roll w below to another roll 10 above over suitable guiding rollers y 1 A box 2 is shown as attached to the tube 1) and inclosin the lower roll w and bein filled with a iquid chemical. It is essential, that the band to impregnated with the chemical shall remain transparent as long as everything is all right in the respective room, but become dark the moment that the dangerous transparent gas passing through the tubes a and a and across the tube 1) acts upon the chemical in the band w. The band to may be moved in any known manner. arranged for unwinding it from the lower roll w and for winding it on the upper roll to and any known mechanism may reversing from time to time the motion of the two rolls to and w and thus keepin the band w moving. Or the band w may e simply shifted by hand, for example by means of a handle wa on the upper rol w so as to remove its portion acted upon by the dangerous transparent gas and rendered more or less opaque from the interior of the tube b and to expose a fresh trans arent portion to ,the rays of light assing f fom the lamp I) through the tubeli to the selenium cell b ,The'li uid chemical in the box 2 may be for examp e a solution of palladium chlorid, which has the property of blackening linen impregnated with it, it dangerous transparent gases such as carbonic oxid, carbonic acid illuminating gas, methane, ethylene, or the like pass across the tube 1) and actupon the linen on both sides. A mixture of a solution of ammoniacal cuprous chlorid with a solution of sodium-palladium chlorid impregnating the linen band '10 has the pro erty of forming a weak cloud'of finely distri uted alladium in the presence of carbonic oxid. t is obvious, that such chemicals coloring ,the band to under the action of dangerous For exam lo a clockwork may be e provided for transparent gases will produce much the same effect as the smoke in the manner described above. From Fig. 2 parts have been omitted, which are shown in Fig. 1', but it is easily to be understood, that these parts may operating the apparatus, the dangerous transparent gases may be chemically treated for actuating a suitable apparatus. For example the dangerous transparent gases may be rendered more or less opaque by combustion. A suitable apparatus serving this purose is illustrated in Fig. 3. A lamp A simiar to a miners safety-lamp isemployed,

- which ma comprise a mantle K with a tube cuit :0 v 12 including a batte C, a wire asket B with a window D in front of the tube 0, a reflector F and a cover H for closingthe u per opening G of themantle' K. At the end 0 the tube 0 a selenium cell E is disposed, which is inserted in a electromagnets c and L. The e ectromagnet c istthe same as that in Figs. 1 and 2 and is arranged to release itsarmature vfor closing a secondary circuit (not shown). The cover H may be pressed downwards by a suitable weight M and is normally attracted by the electromagnet L for permitting the lam A to burn; Where so preferred a secon window similar to D may be rovided in the wire basket B in front of t e reflector F. Air is admitted from below to the lam A in a similar manner as in a miners safety-dam The flame of the lam will emit rays of lig t through the window 1% and the tube C to the selenium cell E for reducing its resistance. This encil of rays of light will be strengthened by the reflector F. Where'so preferred,

a suitable filter may be provided in any known manner for keepingrofi any coal-dust from the lamp. When e damp or carbonic oxid passes through the lamp A, it will burn with a blue flame, whereby the selenium of impregnatinga band of linen or vention remains the same.

primary circ an two.

cell Egwiu be'darkened, so that the strength of the current circulating in the primary circuit a) 'u 11 will be reduced. In consequence .of thisthe electromagnet L will release the cover H which drops and closes the opening G for extinguishing the lamp A and the other electromagnet c Wlll release its armature for closing the secondary circuit and thereby actuating the alarm or other devices. '4

The apparatus described may be varicdun many respects, 'while the principle of the in- I claim:

1. The method of electrically detecting.

dangerous gases, which consists in passing the dangerous gas across rays of 11g t projected from a sourceof light to a selenium 1 cell inserted in a primary circuit for darkening the selenium cell and reducing the strength of the current circulating in the primary circuit, whereby electromagnetic devices are caused to close a secondary circuit for actuatthe current circulating in the primary circuit,

whereby electromagnetic devices are caused to close a secondary circuit for actuating warnlng or other devices.

3. The method of electrically detecting dangerous transparent gases, which consists in passing the gas across rays of light projected from a .source of light to a selenium cell inserted in a primary circuit, and

in chemically rendering the transparent gas opaque for darkening the selenium cell and reducin thestrength of the current circulating int e rimary circuit, whereby electroma netic evices are caused to close a secon ary circuit for actuating warning or other devices.

. HEINRICH FREISE. Witnesses:

.ALFRED POHLMEYER,

M. ENGnLs. 

